writing into a text file

is it possible to write a content in text file that is present out side of the jar using J2me..

i am having a jar file and text file in my mobile.
And from jar i want to write a code to add a content in text file..

is it possible?

Only via the optional JSR-75: http://jcp.org/en/jsr/detail?id=75
If it's not supported by your device you need to use the RMS (Record Management Store) to store data (which is not accessible from outside, if I remember correctly).